Method and apparatus for aligning and securing a cable strain relief

ABSTRACT

The present disclosure relates to a strain relief. In various embodiments, the strain relief includes a strain relief body and at least one alignment feature. The strain relief body is configured to provide support for connection of a cable and/or a wire lead of the cable to a frame. The alignment feature is configured to facilitate alignment of the strain relief relative to the frame. In various embodiments, provided are methods of manufacturing a sensor with a strain relief. The methods may include forming the strain relief about a cable and/or wire leads, wherein the strain relief comprises at least one alignment feature, aligning the alignment feature of the strain relief to a complementary alignment feature of a frame, engaging the complementary alignment feature of the frame with the alignment feature of the strain relief, and electrically coupling the cable and/or wire leads to a circuit.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/009,718, filed Dec. 31, 2007, and is incorporated herein by referencein its entirety.

BACKGROUND

The present disclosure relates generally to medical devices and, moreparticularly, to sensors used for sensing physiological parameters of apatient.

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present disclosure,which are described and/or claimed below. This discussion is believed tobe helpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

In the field of medicine, doctors often desire to monitor certainphysiological characteristics of their patients. Accordingly, a widevariety of devices have been developed for monitoring physiologicalcharacteristics. Such devices provide doctors and other healthcarepersonnel with the information they need to provide the best possiblehealthcare for their patients. As a result, such monitoring devices havebecome an indispensable part of modern medicine.

One such monitoring technique is commonly referred to as pulse oximetry.Pulse oximetry may be used to measure various blood flowcharacteristics, such as the blood-oxygen saturation of hemoglobin inarterial blood and/or the rate of blood pulsations corresponding to eachheartbeat of a patient.

The devices based upon pulse oximetry techniques are commonly referredto as pulse oximeters. Pulse oximeters typically utilize a non-invasivesensor that is placed on or against a patient's tissue that is wellperfused with blood, such as a patient's finger, toe, forehead orearlobe. The pulse oximeter sensor emits light and photoelectricallysenses the absorption and/or scattering of the light after passagethrough the perfused tissue. The data collected by the sensor may thenbe used to calculate one or more of the above physiologicalcharacteristics based upon the absorption or scattering of the light.More specifically, the emitted light is typically selected to be of oneor more wavelengths that are absorbed or scattered in an amount relatedto the presence of oxygenated versus de-oxygenated hemoglobin in theblood. The amount of light absorbed and/or scattered may then be used toestimate the amount of the oxygen in the tissue using variousalgorithms.

Pulse oximetry sensors may include a flex circuit that electricallyconnects various electrical components of the sensor. For example,components of the flex circuit may include an optical emitter, such asan LED, a photodetector and wires forming conductors which electricallyconnect the sensor components and/or allow connection of the sensorcomponents to a pulse oximeter monitor via wire leads contained in acable. During use of such a sensor, mechanical stresses may be placed onthe location where an external cable and its wire leads are attached tothe sensor frame and associated flex circuit. Generally, a strain reliefmay be provided to reduce the effect of the mechanical stresses at thepoint where the cable attaches to the sensor frame.

During the manufacturing process it may be labor intensive to secure astrain relief to the sensor frame and cable prior to and during theprocess of connecting the wire leads of the cable to the flex circuit.Further, aligning the wire leads for proper connection may be a laborintensive task, the difficulty of which may result in wires beingimproperly seated, resulting in the production of poorly functioning ornon-functioning sensors.

SUMMARY

Certain aspects commensurate in scope with the disclosure are set forthbelow. It should be understood that these aspects are presented merelyto provide the reader with a brief summary of certain forms thedisclosure might take and that these aspects are not intended to limitthe scope of the disclosure. Indeed, the disclosure may encompass avariety of aspects that may not be set forth below.

In accordance with various embodiments, a strain relief is provided. Thestrain relief includes a strain relief body and at least one alignmentfeature. The strain relief body is configured to provide support forconnection of a cable and/or at least one wire lead of the cable to aframe. The at least one alignment feature is configured to facilitatealignment of the strain relief relative to the frame.

In accordance with various embodiments, provided is a method ofmanufacturing a sensor with a strain relief. The method includes formingthe strain relief about a cable and/or wire leads, wherein the strainrelief comprises at least one alignment feature. The alignment featureof the strain relief is aligned to a complementary alignment feature ofa frame. The complementary alignment feature of the frame is engagedwith the alignment feature of the strain relief. The cable and/or wireleads are electrically coupled to a circuit.

In accordance with various embodiments, provided is a sensor system. Thesensor system includes a frame, a cable, and a strain relief. The strainrelief includes a first strain relief portion couplable to the frame andcoupled to the cable and a second strain relief portion coupable to thefirst strain relief portion and a portion of the cable, proximate to alocation where the cable exits the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the disclosure may become apparent upon reading thefollowing detailed description and upon reference to the drawings inwhich:

FIG. 1 illustrates a patient monitoring system coupled to amulti-parameter patient monitor and a sensor, in accordance with anembodiment;

FIG. 2 illustrates a perspective view of a strain relief, in accordancewith an embodiment;

FIG. 3A illustrates a strain relief in a frame prior to engaging theframe, in accordance with an embodiment;

FIG. 3B illustrates a strain relief engaged in a frame, in accordancewith an embodiment;

FIG. 4 illustrates a cross sectional view of the strain relief and frameof FIG. 3B, taken along line 4-4 of FIG. 3B;

FIG. 5 illustrates a perspective view the strain relief, the frame, andthe wire leads of FIGS. 3A and 3B aligned to the solder pads of the flexcircuit, in accordance with an embodiment;

FIG. 6 illustrates an exploded view of the two portions of the strain,in accordance with an embodiment;

FIG. 7 illustrates a perspective view of a strain relief formed from twoportions, in accordance with an embodiment;

FIG. 8 illustrates an exploded view of the strain relief prior toassembly in accordance with an embodiment;

FIG. 9 illustrates a cross sectional view of the strain relief and frameof FIG. 3B, taken along line 9-9 of FIG. 3B, in accordance with anembodiment;

FIG. 10 is a flowchart that illustrates a method for forming the strainrelief, in accordance with an embodiment; and

FIG. 11 is a flowchart that illustrates of a method for manufacturing asensor with a strain relief, in accordance with an embodiment.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Various embodiments of the present disclosure will be described below.In an effort to provide a concise description of these embodiments, notall features of an actual implementation are described in thespecification. It should be appreciated that in the development of anysuch actual implementation, as in any engineering or design project,numerous implementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but would nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

According to various embodiments, methods and systems for securing acable and strain relief to a sensor frame during the fabrication of asensor are described. In one embodiment, the cable and wire leads of thecable are secured to the sensor frame via a strain relief that isaligned and secured to the frame. In such an embodiment, the cable andstrain relief may be secured to the sensor frame by sliding the strainrelief into the frame. In another embodiment, the strain relief providesfor aligning the wire leads of the cable for connection to a flexcircuit. In such an embodiment, the strain relief and cable may besecured to the frame with the wire leads in position for soldering, andwith minimal, or at least a reduced amount, of additional alignment ofthe wire leads.

As described herein, various embodiments of the sensor and frame areprovided which are believed to provide simple and secure assembly of asensor including a frame and a strain relief. Prior to discussing suchsensors in detail, it should be appreciated that such sensors aretypically designed for use with a patient monitoring system. Forexample, referring now to FIG. 1, a sensor 10 according to an embodimentmay be used in conjunction with a patient monitor 12. In the depictedembodiment, a cable 14 connects the sensor 10 to the patient monitor 12.As will be appreciated by those of ordinary skill in the art, the sensor10 and/or the cable 14 may include or incorporate one or more integratedcircuit devices or electrical devices, such as a memory, processor chip,or resistor, that may facilitate or enhance communication between thesensor 10 and the patient monitor 12. Likewise the cable 14 may be anadaptor cable, with or without an integrated circuit or electricaldevice, for facilitating communication between the sensor 10 and varioustypes of monitors, including older or newer versions of the patientmonitor 12 or other physiological monitors.

In other embodiments, the sensor 10 and the patient monitor 12 maycommunicate via wireless means, such as using radio, infrared, oroptical signals. In such embodiments, a transmission device (not shown)may be connected to the sensor 10 to facilitate wireless transmissionbetween the sensor 10 and the patient monitor 12. As will be appreciatedby those of ordinary skill in the alt, the cable 14 (or a correspondingwireless transmission) may be used to transmit control or timing signalsfrom the monitor 12 to the sensor 10 and/or to transmit acquired datafrom the sensor 10 to the monitor 12. In some embodiments, the cable 14may be an optical fiber that enables optical signals to be conductedbetween the patient monitor 12 and the sensor 10.

In an embodiment, the patient monitor 12 may be a suitable pulseoximeter, such as those available from Nellcor Puritan Bennett LLC. Inother embodiments, the patient monitor 12 may be a monitor suitable formeasuring tissue water fractions, or other body fluid related metrics,using spectrophotometric or other techniques. Furthermore, the patientmonitor 12 may be a multi-purpose monitor suitable for performing pulseoximetry and measurement of tissue water fraction, or other combinationsof physiological and/or biochemical monitoring processes, using dataacquired via the sensor 10. Furthermore, to upgrade conventionalmonitoring functions provided by the monitor 12 and to provideadditional functions, the patient monitor 12 may be coupled to amulti-parameter patient monitor 16 via a cable 18 connected to a sensorinput port and/or a cable 20 connected to a digital communication port.

In an embodiment, the sensor 10, as depicted in FIG. 1, is a clip-stylesensor that is overmolded to provide a unitary or enclosed assembly. Thesensor 10 may include an emitter 22 and a detector 24 which may be ofany suitable type. For example, the emitter 22 may be one or more lightemitting diodes adapted to transmit one or more wavelengths of light,such as in the red to infrared range, and the detector 24 may be aphotodetector, such as a silicon photodiode package, selected to receivelight in the range emitted from the emitter 22. In the depictedembodiment, the sensor 10 is coupled to a cable 14 that is responsiblefor transmitting electrical and/or optical signals to and from theemitter 22 and the detector 24 of the sensor 10. The cable 14 may bepermanently coupled to the sensor 10, or it may be removably coupled tothe sensor 10—the latter alternative being more useful and costefficient in situations where the sensor 10 is disposable.

The sensor 10 discussed herein may be configured for either transmissionor reflectance type sensing, in various embodiments. Furthermore, thesensor 10 may include various structural and functional featuresdesigned to facilitate its use. An example of such a sensor and its useand construction may be found in U.S. application Ser. No. 11/199,524titled “Medical Sensor and Technique for Using the Same” and filed onAug. 8, 2005, which is hereby incorporated by reference in its entiretyfor all purposes. As will be appreciated by those of ordinary skill inthe alt, however, such discussion is merely an example and is notintended to limit the scope of the present disclosure.

Referring now to FIG. 2, a strain relief 26 of the sensor 10 is depictedin accordance with an embodiment. As depicted, the strain relief 26 mayinclude a single body 28. Further, as depicted in FIG. 2, the strainrelief 26 and the body 28 may include various features that facilitateassembly of the strain relief 26 to a sensor frame, such as a frame 30discussed in further detail below with regard to FIGS. 3A-3B. Forexample, in one embodiment, the body 28 of the strain relief 26 includesextensions 32 that are located on each side of the body 28. Asillustrated, the extensions 32 may include a wing-like structureextending along the length of the body 28 that can be inserted into acomplementary frame slot 34 of the frame 30.

In an embodiments, as depicted in FIG. 3A, the strain relief 26 may beinserted into a void portion 36 of the frame 30, the extensions 32aligned with the frame slots 34, and the strain relief 26 slid in anengagement direction (indicated by arrow 38) toward the frame slots 34until the strain relief 26 is sufficiently seated in the frame 30, asdepicted in FIG. 3B. Accordingly, integrating the extensions 32 into thestrain relief 26 may facilitate rapid and secure assembly of the sensor10. The number, location, size, shape and other characteristics of theextensions 32 and/or frame slot 34 may be varied to accommodate otherembodiments without altering the implementation of the presentdisclosure.

Further, as depicted in FIG. 2 and further depicted in FIG. 4,embodiments of the strain relief 26 may also include a strain reliefdetent feature 40 that can be configured to mate with a complementarycapture feature 42 of the frame 30. The engagement of the detent feature40 with the complementary capture feature 42 may facilitate securing thestrain relief 26 to the frame 30 when the extensions 32 and frame slot34 are aligned, and the strain relief 26 is slid into position (seeFIGS. 3A, 3B, and 4). For example, as depicted in FIG. 4, the strainrelief detent feature 40 may include a raised lip or extension and thecomplementary capture feature 42 includes a recessed notch, channel, orthe like. When the strain relief 26 is mated with the frame 30, thestrain relief detent feature 40 may engage the complementary capturefeature 42. The configuration, design, and number of the strain reliefdetent feature 40 and the strain relief capture feature 42 may be variedto facilitate retention of the strain relief 26 to the frame 30. Forexample, in other embodiments, the detent feature 40 may be disposed onthe frame 30 and the complementary capture feature 42 may be disposed onthe strain relief 32. Further, any number of detent features 40 and/orcapture features 42 may be employed.

The engagement of the strain relief detent feature 40 to the strainrelief capture feature 42 may be accompanied by an audible indicationcapable of being heard by an assembler. The audible indication mayinclude a confirmatory click or snap upon engagement of the strainrelief 26 and the frame 30. The audible indication may alert theassembler that the strain relief 26 and the frame 30 have been properlysecured to one another. For example, the detent feature 40 and thecapture feature 42 may engage one another to produce an audible snap orclick within the last 10% of coupling the strain relief 26 to the frame30 such that the audible snap is a signal to the assembler that thecomponents have been sufficiently engaged.

In addition to providing support for the cable 14, the strain relief 26may also separate and align wire leads 44 of the cable 14, asillustrated in FIGS. 4 and 5. Separating and aligning the wire leads 44may facilitate connection of the wire leads 44 to other devices, such asa flex circuit 46 including soldering pads 48. For example, where thecable 14 includes a crimp 49, the portion of the wire leads 44 betweenthe crimp 49 and ends 50 of the wire leads 44 may be separated andcoupled to respective electrical connectors, such as the soldering pads48. By aligning the leads 44 at the time the strain relief 26 may besecured about the wire leads 44, the step of separating the wire leads44 before securing the wire leads 44 to the flex circuit 46 may besimplified or eliminated, thereby, reducing the labor involved inassembling the sensor 10. Further, the separation and alignment of thewire leads 44 provided for by the strain relief 26 may stabilize thewire leads 44 during the assembly process, thus, further reducing thelabor required to hold the wire leads 44 in place for connection (e.g.,soldering). For example, as depicted in FIGS. 4 and 5, the strain relief26 may be formed with the crimp 49 already installed about the cable 14and six of the wire leads 44 properly positioned for soldering the ends50 of the wire lead 44 to the soldering pads 48.

In another embodiment, the strain relief 26 may be formed from multipleportions that can be disposed about the wire leads 44. For example, asillustrated in FIG. 6, the strain relief 26 may include a top portion 51and bottom portion 52. In the depicted embodiment, the top portion 51and the bottom portion 52 each include a series of pass-through channels53 that are configured to accept the wire leads 44. Each wire lead 44may be set in a respective channel 53, and the top 51 and bottom 52portions subsequently secured about the wire leads 44 and the crimp 49.For example, in an embodiment including the six wire leads 44, asdiscussed with regard to FIG. 5, the top portion 51 and the bottomportion 52 may each include six channels 53 that can each accept arespective wire lead 44. The number, arrangements, shape, and size ofthe channels 53 may be varied to accommodate various applications.

In various embodiments, the strain relief 26 may include two differentregions, in another embodiment. For example, referring now to FIG. 7, inthe illustrated embodiment, the strain relief 26 includes a firstportion 54 and a second portion 56. The first portion 54 may include astructure that provides structural support and retention of the strainrelief 26 in the frame 30. For example, in the depicted embodiment, thefirst portion 54 includes extensions 32 and the portion of the body 28that may be disposed internal to the frame 30. The second portion 56 mayextend about the cable 14 and, thus, may provide flexible support ofcable 14 and reduce the likelihood of the cable 14 bending and wearingat the point of attachment to the first portion 54 and/or the frame 30.

In an embodiment, the first portion 54 and the second portion 56 may beformed from the same or different materials. In the case of differentmaterials being employed for the first and second portions 54 and 56,the first portion 54 may employ a relatively hard material and thesecond portion 56 may be formed from a relatively soft material. Forexample, the first portion 54 may be formed from materials such aspolypropylene and/or polystyrene, and the second portion 56 may beformed from a softer material, such as an ethylene propylene rubber. Inother embodiments, the second portion 56 may be formed from materialshaving a durometer of about 45 Shore A to about 70 Shore A.

In various embodiments, the first portion 54 and the second portion 56may be formed in a variety of manners. For example, in one embodiment,the strain relief 26 may include the first portion 54 and the secondportion 56 formed integrally. In other words, the first portion 54 andthe second portion 56 may be formed together such that they aremechanically coupled to one another to form the body 28. For example, asillustrated in FIG. 7, the first portion 54 may be formed to include acavity 58, and the second portion 56 subsequently formed (e.g., molded)into the cavity 58, or vice versa, to form the strain relief 26.

In another embodiment, the first portion 54 and the second portion 56may be formed independently from one another and subsequently secured toone another to form the strain relief 26. For example, as depicted inFIG. 8, the cavity 58 of the first portion 54 may be configured to matewith a complementary protrusion 60 that extends from the second portion56. During assembly, the protrusion 56 may be inserted into the cavity58 to secure the first portion 54 and the second portion 56 to oneanother. For example, an interference fit between the protrusion 60 andthe cavity 58 may provide enough friction to couple the first portion 54and the second portion 56 to one another.

Another embodiment may employ detent features that are configured tofacilitate coupling the first portion 54 and the second portion 56. Forexample, as further depicted in FIG. 8, the first portion 54 may includedetent features 62 that are mated with complementary capture features 64disposed on the surfaces of the second portion 56. For example, thedetent feature 62 may include a raised surface, bump, or lip, and thecapture feature 64 may include a depression, recess, notch, or lip thatis configured to accept the detent feature 62. Accordingly, mating thedetent feature 62 with the capture feature 64 may secure the firstportion 54 to the second portion 56. The detent and capture features 62and 64 may be arranged in a variety of manners. For instance, thecapture feature 64 and/or the protrusion 60 may be integral to the firstportion 54, and the detent feature 62 and/or the cavity 58 may belocated integral to the second portion 56. Further, the number,location, size and combination of detent features 62 and capturefeatures 64 may be varied. For example, a combination of detent andcapture features 62 and 64 may be employed on, both, the first portion54 and the second portion 56.

In various embodiments, the engagement of the detent feature 62 to thecapture feature 64 may be accompanied by an audible indication capableof being heard by an assembler. The indication may be of the form of aconfirmatory click or snap upon engagement of the first portion 54 andsecond portion 56. The audible indication may alert the assembler thatthe first portion 54 and the second portion 56 have been properlysecured to one another. For example, the detent feature 62 and thecapture feature 64 may engage one another and produce the audibleindication within the last 10% of coupling the first portion 54 to thesecond portion 56 such that the audible indication is a signal to theassembler that the components have been sufficiently assembled.

Turning now to FIG. 9, an embodiment of the strain relief 26 may includea surface feature 68 that substantially conforms to the shape and/orcurvature of the assembled sensor 10, including an overmold. Forexample, in the illustrated embodiment, the surface feature 68 (e.g.,the top surface) of the strain relief 26 includes a curvature that issubstantially the same as the curvature of an overmold 70 that isdisposed about the sensor 10 during a fabricating process. In such anembodiment, the surface feature 68 may be shaped or contoured to providethe desired shape or curvature of the sensor 10 when overmolded. Forexample, as depicted in FIG. 9, the surface feature 68 may include adome that is substantially consistent with the curvature of the top ofthe sensor frame 30. By conforming the surface feature 68 to the shapeof the overmold 70, an additional shaping component does not need to beadded between the strain relief 26 and the overmold 70. Further, theabsence of such a shaping component may allow an overall height 72 ofthe sensor 10 to be reduced. As will be appreciated by those of ordinaryskill in the art, the shape of the surface feature 68 may be varied toaccommodate the resulting shape of the overmold 70, taking into accountthe consistency of the thickness of the overmold 70 over the surfacefeature 68.

In another embodiment, the strain relief 26 may occupy a majority of avoid region 74 in the frame 30. For example, as depicted in FIG. 9, thestrain relief 26 may occupy a majority of the internal void region 74 ofthe frame 30, thereby preventing air from otherwise filling the voidregion 74. Displacing some or all of the air that may otherwise remainin the frame 30 may prevent or reduce the formation of air bubblesduring an overmolding process.

In various embodiments, materials suitable for forming the strain relief26 may include thermoplastic elastomers (TPE) that may facilitatechemically bonding to an overmold material 70, and may providesufficient rigidity to support the retention of the cable 14 in theframe 30. For example in one embodiment, the strain relief 26 may beformed from polypropylene which is generally capable of chemicallybonding to overmold materials, including GLS 2706 and GLS G6713,available from GLS Corporation headquartered in McHenry, Ill., USA.

In another embodiment, the material used to form the strain relief 26may include a transparent material. For example, in one embodiment thestrain relief 26 may be formed of a transparent polypropylene material.A transparent material may provide for visual inspection of the strainrelief 26, and may facilitate alignment, assembly, and/or final testingof the sensor 10. For example forming the strain relief 26 oftransparent material may facilitate inspection of the condition andplacement of the wire leads 44 and the wire crimp 49 prior to assemblyand or overmolding of the sensor 10. As will be appreciated by those ofordinary skill in the art, other materials may be employed that providesufficient support and transparency (e.g., transparent polystyrene).

FIG. 10 is a flowchart that illustrates a method 80 of manufacturing thestrain relief 26 about the wire leads 44, according to an embodiment.First, the cable 14 may be stripped of insulation and the individualwire leads 44 stripped and separated (Block 82). The crimp 49 may thenbe placed about the end of the cable 14 (Block 84) to prevent separationof the cable 14 proximate the location where the wire leads 44 areseparated. The wire leads 44 may then be spread, aligned, and secured(Block 86) for coupling to the flex circuit 46. After the wire leads 44are secured into relative placements, the wire leads 44 may be suspendedin a mold used to form the strain relief 26 (Block 88). With the wireleads 44 suspended in the mold, the strain relief 26 material (e.g.,polypropylene) may be injected about the suspended wire leads 44 to fillthe mold and form the strain relief 26 (Block 90).

In various embodiments, the method 80 may provide for a solid strainrelief 26 molded about the aligned wire leads 44. As will be appreciatedby a person of ordinary skill in the art, the method 80 of forming thestrain relief 36 about the aligned wire leads 44 may include othermethods to secure the strain relief 26 about the aligned wire leads 44.For example, as depicted in FIG. 6, the strain relief 26 may include topand bottom portions 51 and 52 that include multiple pass-throughchannels 53 that are configured to accept the wire leads 44 and thecrimp 49. The wire leads 44 may set in the pass-through channels 53 andthe top and bottom portions 51 and 52 may then be secured about the wireleads 44 and crimp 49 to form the strain relief 26 about the alignedwire leads 44.

FIG. 11 is a flowchart that illustrates a method 100 of manufacturing asensor 10 in accordance with an embodiment. The method 100 provides formanufacturing of the strain relief 26, assembly of the strain relief 26to the sensor frame 30, and overmolding of the assembled sensor 10. Forexample, the embodiment of FIG. 11 provides for forming strain relief 26with aligned wire leads 44 (Block 102) as described herein.

In various embodiments, the method 100 may also include aligning andsecuring the strain relief 26 to the frame 30 (Block 102). Securing thestrain relief 26 to the frame 30 may provide for mechanically aligningand fastening the strain relief 26 and holding the strain relief 26 inplace during subsequent assembly and use. For example, as describedpreviously, securing the strain relief 26 to the frame 30 may requirealignment of the extensions 32, sliding the strain relief 26 into theframe 30, and continuing to slide the strain relief 26 until the strainrelief detent feature 40 engages the complementary capture feature 42.As described previously, the engagement of the strain relief detentfeature 40 and the capture feature 42 may be indicated audibly.

To facilitate connection of the wire leads 44 to flex circuit 46, themethod 100 may also include connecting the wire leads 44 of the cable 14to the flex circuit 46 (Block 106). As will be appreciated by a personof ordinary skill in the art, connecting the wire leads 44 to the flexcircuit 46 may include various means of electrical coupling, includingsoldering the ends 50 of the wire leads 44 to the solder pads 48.

In various embodiments, the method 100 may also include overmolding theassembled frame 30 and strain relief 26 (Block 108). For example, afterthe strain relief 26 has been secured to the frame 30, it may bedesirable to overcoat the sensor 10 with an overmold material to provideprotection of the assembly (Block 108). As discussed previously,overmold materials may include GLS 2706 and GLS G6713 or any othersuitable overmold material. During the overmold process, the curvatureof the shape of the strain relief 26 may fill a majority of the voidregion 74 in the frame 30 and thereby reduce the amount of overmoldmaterial required to provide the desired shape of the sensor 10, as wellas, reduce the propensity of the overmold 70 to form air pockets. Theovermold 70 may provide additional protection to the sensor 10 andsecure the strain relief 26, in addition to providing an ergonomicpackage for the user of the sensor 10.

While the medical sensors 10 discussed herein are some examples ofovermolded or coated medical devices, other such devices are alsocontemplated and fall within the scope of the present disclosure. Forexample, other medical sensors and/or contacts applied externally to apatient may be advantageously applied using the strain relief 26 havingalignment and retaining features, as discussed herein. For example,devices for measuring tissue water fraction or other body fluid relatedmetrics may utilize a sensor as described herein. Likewise, otherspectrophotometric applications where a probe is attached to a patientmay utilize a sensor as described herein.

While the disclosure may be susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and have been described in detail herein.However, it should be understood that the disclosure is not intended tobe limited to the particular forms disclosed. Rather, the disclosure isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the disclosure as defined by the followingappended claims.

1. A sensor assembly, comprising: a photometric sensor coupled to aframe; a strain relief body capable of providing support for connectionof a cable and/or a wire lead of the cable to the frame; and analignment feature capable of facilitating alignment of the strain reliefrelative to the frame.
 2. The sensor assembly of claim 1, wherein thestrain relief body comprises polypropylene.
 3. The sensor assembly ofclaim 1, wherein the strain relief body comprises a generallytransparent material.
 4. The sensor assembly of claim 1, wherein thestrain relief body comprises a first portion and a second portion,wherein the first portion is capable of facilitating support and/orretention of the strain relief body in the frame, and the second portionis capable of facilitating support of the cable.
 5. The sensor assemblyof claim 4, wherein the second portion comprises a material generallyhaving a durometer rating of about 45 A to about 70 A.
 6. The sensorassembly of claim 4, wherein the two portions are coupled to one anothervia a locking feature.
 7. The sensor assembly of claim 6, wherein thelocking feature facilitates an audible indication when the two portionsare coupled.
 8. The sensor assembly of claim 1, wherein the alignmentfeature comprises an extension configured to align with a complementaryslot on the frame, wherein sliding the extension into the complementaryslot secures the strain relief body to the frame.
 9. The sensor assemblyof claim 1, wherein the strain relief body comprises a retention featureconfigured to engage a complementary retention feature on the frame. 10.The sensor assembly of claim 9, wherein the retention feature isconfigured to provide an audible indication when the retention featureengages the complementary retention feature.
 11. The sensor assembly ofclaim 1, wherein the strain relief body is molded generally about thecable and/or wire leads.
 12. The sensor assembly of claim 1, wherein thestrain relief body comprises two portions configured to facilitatealignment and support of the cable and wire lead, wherein one portioncomprises an accepting channel configured to secure the cable and/or thewire lead, and wherein the two portions are secured to one another aboutthe cable and/or the wire leads.
 13. The sensor assembly of claim 1,wherein the strain relief body comprises a surface feature thatgenerally conforms to the shape and/or curvature of the frame.
 14. Amethod of engaging with a strain relief, comprising: forming a strainrelief about a cable and/or wire lead, wherein the strain reliefcomprises an alignment feature; aligning the alignment feature of thestrain relief to a complementary alignment feature of a frame; engagingthe complementary alignment feature of the frame with the alignmentfeature of the strain relief; and electrically coupling the cable and/orwire lead to a circuit disposed on the frame and in electricalcommunication with a photometric sensor coupled to the frame.
 15. Themethod of claim 14, wherein the alignment feature comprises extensions,and wherein the complementary alignment feature comprises a slotconfigured to receive the extensions.
 16. The method of claim 14,comprising engaging a retention feature of the strain relief to aretention feature of the frame.
 17. The method of claim 14, whereinelectrically coupling the cable and/or wire lead to the circuitcomprises soldering the cable and/or wire lead to soldering pads of thecircuit.
 18. The method of claim 14, wherein forming the strain reliefabout the cable and/or wire lead comprises enclosing the cable and/orwire lead between two portions of the strain relief, and disposing thecable and/or wire lead in respective channels of the strain relief. 19.A sensor system, comprising: a frame; a photometric sensor coupled tothe frame; a cable; and a strain relief comprising: a first strainrelief portion capable of coupling to the frame and to the cable; and asecond strain relief portion capable of coupling to the first strainrelief portion and a portion of the cable proximate to a location wherethe cable exits the frame.